Theoretical Calculations
Mostrando 13-24 de 385 artigos, teses e dissertações.
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13. Theoretical Calculations on the Mechanism of Hydrogenation of Diphenylacetylene over Pdn (n = 1-4) Clusters
Diphenylacetylene (DPA) is a precursor of stilbene and benzil, and reduction of DPA or its derivatives with metallic reagents is both an old and contemporary topic of research. By means of density function theory (DFT) calculations, a detailed investigation of the mechanism of the hydrogenation of DPA over Pd clusters was carried out at the molecular level.
J. Braz. Chem. Soc.. Publicado em: 2020-10
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14. Antibacterial Activity of 2-Amino-1,4-naphthoquinone Derivatives against Gram-Positive and Gram-Negative Bacterial Strains and Their Interaction with Human Serum Albumin
A series of 2-amino-1,4-naphthoquinone derivatives (NQA-NQF) was synthesized by alternative methods (ultrasonication and microwave irradiation), with yields ranging from 40 to 71%, and without the need of further recrystallization. Each compound was evaluated against four Gram-positive (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus and Baci
J. Braz. Chem. Soc.. Publicado em: 2020-09
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15. A Simple Fluorescent Chemosensor for Detection of Zinc Ions in Some Real Samples and Intracellular Imaging in Living Cells
A new designed fluorescent chemosensor TYMN ((E)-1-((thiazol-2-ylimino)methyl)naphthalen-2-ol) for highly sensitive and selective tracing of trace amount of Zn2+ ions in some real samples was synthesized and characterized. The sensor TYMN can detect Zn2+ ions via fluorescence enhancement with a high selectivity over a wide range of metal ions, especially Cd2
J. Braz. Chem. Soc.. Publicado em: 2020-08
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16. Should kidney transplants during the COVID-19 pandemic be canceled or maintained?
The preparation, characterization, theoretical calculations and biological application of four RuII complexes with 2-picolinate (pic), 2,2’-bipyridine (bipy) and P-P as ligands [P-P = 1,1-bis(diphenylphosphino)methane (dppm-1), 1,2-bis(diphenylphosphino)ethane (dppe-2), 1,3-bis(diphenylphosphino)propane (dppp-3) or 1,1’-bis(diphenylphosphino)ferrocene (d
Rev. Assoc. Med. Bras.. Publicado em: 2020-07
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17. New Heteroleptic RuII/Diphosphine Complexes with Cytotoxicity against Human Breast and Murine Ascitic Sarcoma 180 Tumor Cells
The preparation, characterization, theoretical calculations and biological application of four RuII complexes with 2-picolinate (pic), 2,2’-bipyridine (bipy) and P-P as ligands [P-P = 1,1-bis(diphenylphosphino)methane (dppm-1), 1,2-bis(diphenylphosphino)ethane (dppe-2), 1,3-bis(diphenylphosphino)propane (dppp-3) or 1,1’-bis(diphenylphosphino)ferrocene (d
J. Braz. Chem. Soc.. Publicado em: 2020-07
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18. Pesquisas em políticas de comunicação em contextos de crise
By way of Density Functional Theory (DFT)-based computational methods with commercially available software, the computational work of which about the molecular properties, the vibrational modes and vibrational frequencies of finasteride were accomplished for the first time. In order to gain a deeper and more thorough understanding of the molecular structure
Intercom, Rev. Bras. Ciênc. Comun.. Publicado em: 2020-05
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19. VIBRATIONAL SPECTROSCOPIC INVESTIGATION AND MOLECULAR STRUCTURE OF A 5α-REDUCTASE INHIBITOR: FINASTERIDE
By way of Density Functional Theory (DFT)-based computational methods with commercially available software, the computational work of which about the molecular properties, the vibrational modes and vibrational frequencies of finasteride were accomplished for the first time. In order to gain a deeper and more thorough understanding of the molecular structure
Quím. Nova. Publicado em: 2020-05
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20. Crystal Structure and 1H NMR Experimental and Theoretical Study of Conformers of 5-Methyl-1-(4’-methylphenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester and 5-Methyl-1-(phenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester
We reported experimental and theoretical investigation of conformers of 1,2,3-triazole derivatives, substances of exclusively synthetic origin, subject of extensive studies, because of several biological properties, such as antiviral, antimicrobial and antileishmaniasis. We reported molecular/supramolecular X-ray structures of antiophidian compounds I and II
J. Braz. Chem. Soc.. Publicado em: 2020-05
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21. TD-DFT Analysis of the Dissymmetry Factor in Camphor
The fact that the dissymmetry lgeb (g-factor) of camphor is large has been known for decades, and the interpretation of the observed data has also been known for a long time. However, due to the ability of quantum chemical methods to describe chiroptical phenomena more appropriately, additional approaches based on these methods have been successful employed.
J. Braz. Chem. Soc.. Publicado em: 2020-03
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22. THEORETICAL CALCULATIONS ABOUT THE THERMAL STABILITY AND DETONATION CHARACTER OF NITRAMINO-SUBSTITUTED PYRROLE
A series of nitramino-derivatives of pyrrole were designed through introducing the nitramino group into pyrrole ring to look for high-energy-density compounds. The molecular stabilities are explored thoroughly based on the calculated heats of formation, bond dissociation energy, and bond order at the B3PW91/6-311+G(d,p) level. The results indicated that the
Quím. Nova. Publicado em: 2020-03
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23. Experimental and Theoretical Study of LiMn2O4 Synthesized by the Solution Combustion Method Using Corn Starch as Fuel
Lithium manganese oxide, LiMn2O4, was synthesized in two temperature stages, where the first consisted by an ecofriendly solution combustion method at 300 °C. Finally, the as-burned powders were thermal treated at 500 and 700 °C. The structural and morphological changes were evaluated by the Rietveld method and density functional theory (DFT) calculations.
J. Braz. Chem. Soc.. Publicado em: 2020-02
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24. Structural Study of Phenolic Acids by Triple Quadrupole Mass Spectrometry with Electrospray Ionization in Negative Mode and H/D Isotopic Exchange
This work reports the theoretical and experimental study of fragmentation reactions in the gas phase of five phenolic acids using triple quadrupole mass spectrometry by electrospray ionization in negative ionic mode, as well as the isotope exchange experiments. MS/MS spectra were analyzed to suggest the fragmentation mechanisms, while theoretical calculation
J. Braz. Chem. Soc.. Publicado em: 2020-02